Key pulsing sender for telephone systems



Feb. 24, 1942. M. s. SNELL ET AL 7 2,274,100

KEY PULSING SENDER FOR TELEPHONE SYSTEMS Filed Jan. 20, 1938 2 Sheets-Sheet-l MS. $NLL gif' ERG. WRIGHT AT TORNFV Feb. 24, 1942. M. s. SNELL ET AL 2,274,100

KEY PULSING SENDER FOR TELEPHONE SYSTEMS Filed Jan. 20, '1938 2 Sheets-Sheet 2 NQQ /N I/E N TORS N at ATTORNEY Patented Feb. 24, 1942 KEY 'PULSING SENDERFOR" TELEPHONE SYSTEMS -Maurice S. Snell and Esmond P.) G. Wright, London, England, assignorsto Western Electric- Company, Incorporated, New York N. Y.,,a.cor-

poration of, N ew, York Application January 20, 1938;. SerialfNo; 185,858 In Great Britain February-12; 1937 This invention relates to automatic telephone exchange systems and more particularly to a key pulsing sender for enabling an operator to control the setting of selector switches for establishing connections todesired subscriberslines.

It has been foundthat connections requiring the assistanceor services'of an operator in their establishment can be more expeditiously handled if-=' the operators dialis replaced by a keyset since the operatoris enabled to operate the keyset isterdigits 1 to '0', inclusive, keyed by the operator on a ten-button keyset, the condensers, being charged negatively to register digits 1 to 5, inclusive, or positively to register digits 6 tov inclusive.

T'Wo condenser timed relays-are provided for generating impulses. which are transmitted for setting selector switches and for operating a keys at a much faster rate than she could operate a dial. This operating procedure is particularly advantageous in private branch exchange systemssince less time is consumed by operators iii-establishing desired connections and thus fewer operators are required and they have more spare time-to attend to other duties Whichmay be assigned to them.

' groupsof' condensers. The present invention re- 1ates-to a key pulsing sender of the latter type in which groupsof condensers are employed as digit registers and has for its object'the provision of asender circuit which is simpler in construction, less expensive to manufacture and to maintain and morereliable'in operation.

In accordance with the embodiment of the inventiorrl'selected as illustrative, these objects areattained by the provision of as many groups. of'condensers serving" as registers as are required to registerthe maximum number ofdigits of a subscriber s nuinberz To simplify the disclosure, it has-been assumed that the sender is" allocated to the use of anoperator in a private branch exchange system from which connections may-be extended totsubscrib'ers lines having three-digit train of three counting relays, each digit series of "impulses transmitted being terminated by a polarized stop relay under the control of the: counting relays and the condenser registers. For successively associating the groups of. condensers with the keyset during. the keying of thedi'gits of a line number and for thereafter successively associating the groups-of condensers successively with the counting and stop relays to. control the transmission of series of impulses for setting selector switches in accordance with the digits registered by the groups of condensers, a single set of sequence relays is provided;

While-the sender has been disclosed as applicabletothe control of selector switches controlled by directive impulses, it is to be understood that its applicability is not so limited, but that by obvious modifications itcould be applied to tele phone systems employing other Well-known types of switching apparatus.

For a more complete understanding of the invention reference may be had to the following" detailed description taken in connection .with the accompanying drawingsin which:

Fig. 1 shows a ten-button keyset for the use of an operator in registering the digits of line numbers and such other control equipment of an operators position as is deemed necessary to a comprehension of the invention; and

Fig. 2 shows the equipment of a register sender.

Fora more complete disclosure of the-invention, Fig. 2 should beplaced beneath Fig. 1 with the lines extending toward the upper margin thereof in alignment with the corresponding lines extending toward the lower'margin of Fig. 1.

' For amore complete disclosure-of the operators directory numbers; It will, of course, be obvious of more than three digits and could be used, for 1 example, at A operators or toll operators switchboard positions. Eachgroup of condensers comprises-h ve condensers; any one of which may 1 be charged either positively'or negatively to regposition equipment shown schematically in Fig. 1, reference may be had to British Patent No; 476,048, granted to E. P. G. Wright and Ci C'. Hartley;

It will be assumed that in response to the i1- lumination of a signal lamp, not shown. indicating that the services of the operator are required for completing a desired connection to a line'whosedirectory number is 275 and which number has been communicated to the operator by the calling subscriber in the manner disclosed V prepares a locking circuit for itself over its No. 3

contact and conductor SLL, connect ground over its No. 2 contact, the No. 4 back contact of relay NU, the No. 3 back contact of relay PC to conductor GD for supplying a holding ground for the relays of the sender of Fig. 2 and over its No. 6 front contact supplies operating and holding ground for relays of the position equipment of Fig. 1.

The operator now proceeds to depress keys of the keyset KS to record the number of the desired subscribers line communicated to her by the calling subscriber. Under the assumption that the number of the desired subscribers line is 275, she Will first depress the No. 2 key of the keyset whereupon an operating circuit is established for relay PP extending from ground over the right contacts of the operated key, conductor I I to battery through the winding of relay PP. Relay PP operates, opens the normally closed charging circuit of condenser Cl extending over the No. 1 and No. 2 back contacts of relay PP, opens at its No. 3 back contact a discharge circuit for condenser C2, at its No. 3 front contact closes a charging circuit for condenser 02' extending from ground, through this condenser and resistance Rl to battery and at 7 its 'No. 4 contact establishes a circuit from battery, through resistance R2, conductor l2, the left contacts of the operated key, conductor [3, the' No. 3 back contact of transfer relay XX to ground through condenser Cbl of the first group of-register condensers RGI. Condenser Cbl now becomes negatively charged to register the keyed digit 2.

When the operator thereafter releases the depressed key, relay PP releases, opening the charging circuit just traced through condenser Cbi, reclosing the charging circuit for condenser C-l, opening the charging circuit of condenser C2 and establishing a discharge circuit for condenser C2 extending from ground, through this condenser, over the No. 3 back contact of relay PP, the No. 8 back contact of relay CA, the No. 3 back contact and upper winding of sequence relay X to ground.

' The discharge of condenser C2 over this circuit operates sequence relay X which thereupon locks in a circuit from battery through its lower winding and No. 4 contact, No. 3 back contact of sequence relay Z to ground on conductor GD and at its No. 2 contact establishes an obvious operating circuit for transfer relay XX. Relay XX now operates, disconnecting at its back contacts the condensers of the first register RGI from the group of conductors 15 extending to the keyset and connecting the condensers of the second register RG2 over the back contacts of transfer relay YY and front contacts of transfer relay XX to the group of conductors. t

.The operator next depresses the No. 7 key of the keyset whereupon an operating circuit for relay PP is established extending from ground on conductor NUL, the right contacts of the operatedkey, conductor H to battery through the winding of relay PP. Relay PP operates again closing the charging circuit for condenserC2 and closing a discharging circuit for charged condenser Cl which may be traced from ground, through resistance R3, the No. 1 front contact of relay PP, condenser C l, the N o, 2 front contact of relay PP, conductor M, the left contacts of the operated key, conductor l3, the No. 3 front contact of transfer relay XX, the No. 3 back contact of transfer relay YY, through condenser GM of the second register RG2 to ground. Condenser Ci, which is of higher capacity than register condenser C122, therefore discharges into condenser Cb2, charging it positively to register the second keyed digit '7.

When the operator thereafter releases the depressed key, relay PP releases, opening the charging circuit just traced through condenser CD2, closing the charging circuit of condenser Cl which may now be traced from ground over the No. 2 back contact of relay PP, condenser Cl the No. 1 back contact of relay PP, through resistance R4 to battery, opening the charging circuit of condenser C2 and closing a discharge circuit for this latter condenser extending from ground, through condenser C2, over the No. 3 back contact of relay PP, the No. 8 back contact of relay CA, the No. 3 front contact of sequence relay X, thence over the No. 4 back contact and upper winding of sequence relay Y to ground. The discharge of condenser C2 over this circuit operates sequence relay Y which thereupon locks in a circuit from battery through its lower winding and No. 3 contact, the No. 3 back contact of sequence relay Z to ground on conductor GD and at its No. 2 contact establishes an obvious operating circuit for transfer relay YY. Relay YY now operates, disconnecting at its back contacts the condensers of the second register RG2 from the group of conductors 15 extending to the keyset and connecting the condensers of the third register RG3 over its own front contacts and the front contacts of transfer relay XX to the group of conductors.

The operator next depresses the No. 5 key of the keyset whereupon an operating circuit for relay PP is established which may be traced from ground over the right contacts of this key, conductor H, through the winding of relay PP to battery. Relay PP operates again closing the charging circuit for condenser C2, prepares a discharge circuit for condenser CI which, however, is not effective at this time, and at its No. 4 contact establishes a circuit from battery through resistance R2, conductor I2, the left contacts of the operated key, conductor I6, the No. 6 front contact of transfer relay XX, the No. 6 front contact of transfer relay YY, through condenser C63 of the third register RG3 to ground. Condenser Ce3 now becomes negatively charged to register the third keyed digit 5.

When the operator thereafter releases the depressed key, relay PP releases, opening the charging circuit of condenser Ce3 just traced, closing the charging circuit of condenser Cl, opening the charging circuit of condenser C2 and closing a discharge circuit for this latter c'ondenser which may be traced from ground, through condenser C2, over the No. 3 back contact of relay PP, No. 8 back contact of relay CA, the No. 3 front contact of sequence relay X, the No. 4 front contact of sequence relay Y to ground through the upper winding of sequence relay Z.

The discharge of condenser C2 over this circuit operates sequence relay Z which thereupon looks from battery, through its lower winding and No. 4 contact to ground on conductor GD, opens at its No. 3 back contact the locking circuits of sequence relays X and Y which now release, closes at its No. 5 contact an obvious operating circuit for relay ZZ and over its No. 1 contact establishes a circuit for starting the operation of the impulse generating relays A and AA.

2,224.; too

' Relay ZZ. upon. operating; connects ground. to.

conductor. SLLto hold relay S;of.'the operator's position circuit operatedand; over its lower contact extends groundflon conductor GD to the locking contactsof sequence relays-X and, Y preparatory. to locking these. relays: upon their sub:-

sequent operation;

crating-circuitior relay PP which then. operates atelyoperate in this. circuit, but. condenser C3.

becomes. charged and' when the charging'current through the: condenser: decays,. relay A then operates, closes a charging: circuit for condenser- C4- over its-No; 2.front contactandzthrough resistance R6 to battery,v closes a circuit; from ground over its: No.. 4 :contact; thence in parallel through the: windingzof: relay AA and condenser C5 to battery through resistance RT and at its No. 3- contact prepares the operating circuit. of: relay B. Condenser C5 now charges and ascsoon' as the charging current flowing therethrough-decays sufficiently, relay AA operates and-opensthe 0pcrating circuit of relay A, but relay A doesnot immediately release since it is maintained operated by the discharge current from condenser C3" through its winding. As soon a the discharge current from condenser 63' decays sufil'ciently, re.- lay A releases and opens the operating. circuit of rela-ya A-A. Relay AA does not release: immediately, however, since? it is maintained operated until the discharge current from condenser. C5 through its winding decays 'sufficiently. As soon as relay AA- releases; theoperating circuit for. relay A and the charging. circuit: for condenser C3 are reestablished and relay Ar reoperatesin turn causing the reoperation of relay AA. Relays A and AA are thus timedin their operation and release by condensers C3 and. C5 and continue to and atlits No.v 3 front contact establishes the chargingcircuitfor condenser C21 Upon the first. release of impulse generating: relay A, with relay B operated, the. out-pulsing circuit for setting the first group selector is established. which. may be traced from ground over the No.. 1. contact of relay B, the-No. l back contact of relay A, conductor. IL, the No; 1. back contact of relay PB. to. the. control circuit. of the first group selector. At the same time a circuit is. established from ground through condenser C4; the No; 2..back. contactof relay A, theNo. 3.-

front contact of. relay B, the No, 4 back: contact of. counting relay E, the. No. 3 back contact of counting relay D and. through the No. 3 b ack contact and. lower winding of counting relay C to ground. Condenser C4 discharges over this: circuit thereby causing the operation of relay C which thenlocks in a circuit from battery through its. upper winding and. No. 2 contact, the No. 1 back contact of relay D, the lower back contact of polarized: relay P, to ground over the No, 2 contact ofrelay-B. Upon the'next operation of relay A. the out-pulsing circuit is opened and the charging circuit for. condenser 04 is again closed;

When relay A next releases the out-pulsing circuit is. again closed and. a discharge circuit for condenser C4 is closed. as previously tracedto the No. 3 back contact of counting relay'D thence over the No. 3 front contact of counting relay C to ground through the. lower winding of of relay P to ground at'the No. 2contact of relay B and at its No. 1. back contact opens the looking. circuit of relayC which thereupon releases. Uponthe next operation of relay A, the out pulsing circuit is opened and the charging circuit for condenser C4 is again closed.

, Two impulseshave. now. been transmitted over the out-pulsing circuit to the group. selector and at this time counting-relay D. is operated, countguishing the supervisory lamp at'the operators position. As soon asthe second digit keyed has been registered and sequence relay Y- has operated, as previously described, ground is disconnected. from conductor FZL at the No. 5.back contact of sequence relay Y and relay-F2 thereupon releases and. connects; ground tothe sender start conductor STL from ground at the No; 6

front contact ofrelay S7, over the No. .3.bach.con-

tact of relay NU, No.-- 1. back contact of relay No. 2. back contact-of. relay EC and: they No. 4. back contact of relay-:PA. When. the thirdidigit crating relay A, as soon as relay A operates as previously described, through. the winding. of 1 relay B. to battery...

Relay B upon operating, locks overits: No. 4

contact and. the No. 2 contact of. relayZfto; ground on conductor STL independently. of the operated or unoperated. conditionof relay A and,

ing relays C andrEJare unoperated and transfer r; relay XX is unoperated. It having been assumed that condenser Cb! of the first register R C-fl hasbeen charged negatively to. register the first keyed digit- 2, a discharge circuitforcondenser Chi isnow established. This circuit may be traced from ground, through this condenser, the

No. 3 b ack contact of relay XX, the No. 6. back contact. of counting relay E, the No. 4 contact of counting relay D; the No. 5 back contact of counting relay C, thence in parallel to the oppositely poled rectifiers Rp and Rq, the rectifier Rq v being. so poled as to offer a low resistance to the discharge current from. the negatively charged condenserCbl and the rectifier Rpbeing: poled to offer a: high resistance. The effective discharge circuit for condenser Cbii therefore extends through the lower winding of relay Q and the-No. 1 frontcontact of relayA to ground over the No. 1 contact of relay B and the discharge current from. condenser Cbit therefore operates relay Q;'\Vhih thereupon locks in a cirscuit extending from ground over the No. 1' contaetof: relay'B; theNo. 1 front contactupper winding of relay A, the locking contact and upper winding of relay Q, the No; 1. back. Contact of."

'sequencerelayY, the No.- 1 back contact: of set-'- at its No; 5 contact establishes; an obvious. op-

quence relay X, conductor PAL, the No. back contact of relay PB, the No. 3 back contact of relay PR to battery through the winding of relay PA. Relay A is held operated over this circuit to arrest the transmission of further impulses and relay PA is operated,

Relay PA upon operating locks in a circuit from battery through its winding and No, 3 contact, the No. 2 back contact of relay PC, the No. 1 back contact of relay FZ, the No. 3 back contact of relay NU to ground at the N0. 6 contact of relay S and at its N o. 4 contact removes ground from conductor STL thereby releasing relay B. When relay B releases it opens at its No. 1 contact the locking circuits of relays A and Q, opens at its No. 2 contact the locking circuit of counting relay D and at its No. 5 contact opens the operating circuit of relay PP. Relays A, Q, D and PP now release.

Relay PP upon releasing closes a discharge circuit for condenser C2 which may be traced from ground therethrough, over the No. 3 back contact of relay PP, No. 8 back contact of relay CA, thence through the No. 3 back contact and upper winding of sequence relay X to ground. Relay X now operates by the discharge current from condenser C2, locks in a circuit from battery through its lower winding and No. 4 contact and over the lower contact of relay ZZ to ground on conductor GD and closes an obvious circuit for transfer relay XX which now functions to disconnect the condensers of the first register RGI from conductors extending to contacts of the counting relays and to connect the condensers of the second register RG2 with such conductors.

The group selector now trunk hunts in the usual manner and when an idle final selector has been found, relay PR is operated in the manner disclosed in the British patent hereinbefore referred to and locks in a circuit extending from battery, through its winding and No. 2 contact, the No. 2 back contact of relay PB to ground at the No. 1 contact of relay PA. With relay PR operated, ground is reconnected to conductor STL over the No. 6 contact of relay S, the No. 3 back contact of relay NU, the No. 1 back contact of relay FZ, the No. 2 contact of relay PC, the No. 6 front contact of relay PR and the No. 6 back contact of relay PB and when relay A again operates this ground is extended as previously described to the winding of relay B and relay B operates, locks and causes the reoperation of relay PP which again closes the charging circuit of condenser C2.

On the next release of relay A following the reoperation of relay B, the out-pulsing circuit is again closed, but at this time through'the control circuit of the final selector and the discharge circuit for condenser C4 previously traced is extended through the lower winding of counting relay C and relay C operates and locks as before described. On the next operation of relay A, condenser C4 is recharged and the out-pulsing circuit is opened. When relay A again releases the out-pulsing circuit is again closed and the discharge circuit for condenser C4 is extended, as previously described, through the lower winding of counting relay D which thereupon operates, locks and causes the release of relay C.

With counting relay D operated, counting relays C and E unoperated, transfer relay XX operated and condenser 0112 of the second register RG2 positively charged to register the second digit 7, a discharge circuit is now established from ground, through condenser C122, the No. 3 back contact of transfer relay YY, the No. 3 front contact of transfer relay XX, the No. 6 contact of counting relay E, the No. 4 contact of counting relay D, the No. 5 back contact of counting relay C, through rectifier Ego and the lower winding of relay P to ground. Relay P is now operated by the discharge current from condenser Cb2, but since rectifier Rq offers a high resistance, relay Q does not operate. Relay P upon operating locks in a circuit from battery through its upper winding and upper contact, No. 3 normal contacts of relay R to ground at the No. 2 contact of relay B, opens at its lower back contact the locking circuit of counting relay D, which thereupon releases, and establishes a circuit from ground at the No. 2 contact of relay B over the lower front contact of relay P, the No. 1 back contact of counting relay C to battery through the winding of relay R. Relay R operates and locks over its Nos. 1 and 3 front contacts to ground at the No. 2 contact of relay B and at its No. 3 contacts opens the locking circuit of relay P which now releases.

When relay A again operates, the out-pulsing circuit is again opened and condenser C4 is recharged. On the next release of relay A the outpulsing circuit is closed and a discharge circuit for condenser C4 is established as previously traced through the lower winding of counting relay C and relay C operates and locks. In response to the next operation and release of relay A the out-pulsing circuit is again opened and then closed and condenser C4 is charged and with counting relay C operated, is discharged through the lower winding of counting relay D. Relay D thereupon operates, locks and causes the release of counting relay C as previously described.

On the next operation of relay A the outpulsing circuit is opened and condenser C4 is recharged. When relay A again releases, the outpulsing circuit is closed and a discharge circuit for condenser C4 is established as previously traced over the No. 4 back contact of counting relay E, thence over the No. 3 front contact of counting relay D to ground through the lower winding of counting relay E and relay E operates, locks in a circuit from battery through its upper winding and No. 3 contact, over the lower back contact of relay P to ground at the No. 2 contact of relay B and at its No. 1 back contact opens the locking circuit of relay D which now releases.

When relay A again operates, the out-pulsing circuit is opened and condenser C4 is recharged and when relay A again releases, the out-pulsing circuit is closed and a discharge circuit for condenser C4 is established as previously traced over the No. 3 contact of relay B, the No. 4 front contact of counting relay E and through the No. 3 back contact and lower winding of counting relay C to ground. Relay C now operates and locks in a circuit from battery through its upper winding and No. 2 contact, the No. 1 front contact of counting relay E, the lower back contact of relay P to ground at the No. 2 contact of relay B. On the next operation of relay A, the out-pulsing circuit is again opened and condenser C4 is recharged.

When relay A againreleases, the out-pulsing circuit is closed and a discharge circuit for condenser C4 is established as previously traced over the No. 4 front contact of counting relay E, the No. 3 front contact of counting relay C to ground through the lower winding of counting relay D and relay D :operates, locks'from battery through its upper winding and No. -2 contact, over the No. 4 front contact of :relay C, the N052 front contact of relay E, the lower back contact of relay P to ground at the No. 2-contact of relay B.

Relay A again operates, opens the out-pulsing circuit and closesthe charging :circuit for :condenser'C l. r 1

Relay A has .now transmitted seven impulses for setting, the final selector :and when :it next operates with counting irelays:C, D and Eall operated and relay R operated, a :circuitlislestablished from battery through resistance R3,1 lo.'2 front contact of relay R, No. 7 contact :of .relay C, No. 6 front contact of relay D, .No. 5 :contact of relay E, through rectifier Rq and the slower winding of relay Q, the N10. .1 zfrontcontactiofre- 'layAto ground at theNo. 1 contact ofnrelayrB.

Relay Q operates and locks in .a circuit from ground over the No. 1 contact of relay 1B, the No. 1 front contact and upper winding 'of rrelay A, thecontact and upper winding of zrelay'Q, the No. 1 back contact of sequence relay Y, theNoJl front contact of sequence relay X, conductor PBL, the No. 4 contact-of relay PR, through'the winding of relay PB to battery.

Relay A is held operated over this circuit to arrest the transmission of further impulses and relay PB operates, locks'in a circuit extending from battery through its winding and No. :3- contact, the No. 8 contact of relay PA, the No. 1 contact of relay FZ and thence .as traced 'to ground at the No. 6 contact ofrelay S and at its No. 6 back contact disconnects ground from conductor S'IL thereby releasingrelay B which in turn releases relays A, Q, C, D, E, .R and PP.

Relay PP upon releasing closes a discharge circuit for condenser C2 which may be traced from ground therethrough, over the No. 3 :backcontact of relay PP, the No. 8 back contactof relay PA, the No. 3 front contact ofsequence relay X, thence through the No. 4 back contact and upper winding of sequence relay Y to ground. Relay Y now operates by the discharge current from condenser C2, locks ma circuit from battery through itslower winding and No. '3 contact and over theJlowerc'ontacts ofrelayZZ to round on conductor GD and closes an obvious circuit for transfer relay YY which functions to disconnect the condensers-of the secondregisterRGZ from conductors extending .to the contacts of the counting r lays and'to connect the condensers of the third register RG3 withsuch conductors.

Relay PB upon operating also opens the locking circuit of relay PR which then releases and 'reconnects ground from the No. 6 contact of relay S as traced over the No. 2 contact of relay PC,'the No. 6 back co-ntact'of relay PR, the No. '6 front contact ofrelay PB, to conductor STL'and when relay A again operates, relay B operates, locks and causes the reoperation of relay PP. Relay PP upon operating again closes the charging circuit of condenser C2.

On the next release of relay A following the reoperation of relay B, the out-pulsing "circuitis again closed for controlling the rotary movement of the final selector and thedischarge circuit for condenser C4 previously'traced is extended tothe lower winding of counting relay C and relay C operates and locks as before described. On the next operation of relay A, the out-pulsing circuitis opened and the charging circuit for :condenser C4 is closed. When relay again Ereleases the out-pulsing circuit is again'closed and the discharge circuit for condenser 04, is extended a previously traced through the lower winding *of counting relay D which fthereupon operates, locks --and causes the release of relay C. When circuit is closed and the dischargecircuit-o f condenser C4 isestablished as previously traced over the No. 4 back contact of counting relay the No. 3 front contact of counting relay D and thence through the lower winding of counting relay E to ground and relayE operates, locks in a circuit from battery through its upper winding ,and No. 3 contact, thelowerback contact of relay =P-to ground over the No. 2 contact of relay B andat its No. 1 backcontact opens the locking circuit of relay D which thereupon releases. When relay A again operates, theout-pulsing circuit is opened and the charging circuit forcondenser C4 is closed.

On the next release of relayA the out-pulsing circuit is closed andthe discharge circuit-of condenser C4 is established as previouslytraced over the No; 3 contact of relay B, the No. 4 front contact of counting relay E, through the N0. '3back contact and lower winding of counting relay C to ground and relay C operates and locks in a circuit from battery through .its upper winding and No. 2 contact, the No. 1 front contact .ofrelay E thence as traced to ground at the No.2 contact of relayB. When relay A againoperates the out-pulsing circuit is openedand the charging circuit from condenser C4 isclosed. On the next release of relayA the out-:pulsin circuit is closed and the discharge .circuit for condenser C4 is established as previously traced over the No. 4 front contact of counting relay E, the 'No. 3 front contact of counting relay C, through the lower winding of counting relay Dto ground and relay D operates and locks in a circuit from battery through its upper winding and No. Z'contact, the No. 4 contact of relay C, the No. 3 contact of relay E thence to groundiat the No. 2 contact of relay-B. Relay A again operates to open the out-pulsing circuit and to 'CIOSB'IthB charging circuit for condenser C4.

Relay A has now transmitted five impulses in the third digit series'and upon operating with counting relays C, D and E all operated andrelay R unoperated, a discharge circuit is established from condenser Ce3 of the third register RG3 which was assumed to be charged negatively to register the keyed digit '5. This circuit-maybe traced from ground through this condenser lover I. the No. 6 front contact of transfer relay 'YY,'the

counting relay C, the N 0.6 front contact of counting relay D, the No. 5 contact of counting relay E "through "rectifier Rq, lower winding of relay-Q,

No. 1 front contact of relay A to ground at the No. 1 contact of relay B. Relay Q operates'and locks in a circuit from ground at the No. 1 contact of relay B, through the No. 1 frontcontact and upper winding of relay A, the contactan'd upper "winding of relay Q, the No. 1 frontcontact of sequence-relay Y, conductor PCL, the No.4 contact of relay PB, the No. 5 contact 'of relay PR, through the winding of relay PC to battery.

Relay A is held operated over 'thiscircuit to arrest the transmission of furtherimp'ulses and relay PC operates,locks over its No. 1 contact to the locking circuitpreviously traced forrelay PB and opens atits N0. 2 contactthelocking circuit of relay PA. Relay PA thereupon releases openvi ng at its No. 8 contact the locking circuit of relays PB and PC which thereupon release. Whenrelay PC operated it removed ground at its No. 2 contact from conductor STL thereby releasin relay B which in turn releases relays A, Q, C, D, E and PP. Relay PC upon operating also at its No. 3 contact disconnects ground from conductor GD thus restoring all other operated relays of the sender.

While the control of registration for only the three digits 2, 7 and 5 has been described it is believed that it will be obvious how the remaining digits may be registered, it being borne in mindthat the a, b, c, d and e condensers of any register are charged negatively by the depression of digit keys 1, 2, 3, 4 and 5, respectively, and that these condensers are charged positively by the ,,depression of digit keys 6, 7, 8, 9 and 0, respectively. On out-pulsing for digits 1, 3 and 4 registered by a negatively charged a, c or (1 concountingrelay E being operated alone to establish the'circuit of relay Q through a negatively charged condenser c after three impulses have been transmitted and relays C and E being both operated to establish the circuit of relay Q through a negatively charged condenser d after four impulses have been transmitted.

.On out-pulsing -for digits 6, 8, 9 and 0 registered by a positively charged a, c, d or e condenser of any register, relay P is operated after one, three, four or five impulses have been transmitted and causes the operation and locking of relay R as an indication that five additional impulses should be sent, relay P being operated by, the discharge of a condenser a. with only counting relay C operated, relay P being operated by the discharge of a condenser c with only relay E operated, relay P being operated by the discharge of a condenser 11 when both counting relays C and E are operated and relay P being operated by the discharge of condenser c with all of the counting relays C, D and E operated. When relay P operates, the operated counting relays are released but impulsing is not arrested, the transmission of five additional impulses being arrested by the operation of relay Q only after the counting relays C, D and E have been reoperated and remain operated.

Should the operator make an error in keying up a line designation or for any other reason should desire to cancel the number registered, she may operate the release key RK thereby closing a circuit over conductor CAL through the winding of relay CA to battery. If transfer relay XX is not at the time operated, relay CA upon operating will establish circuits from ground over its Nos. 2 to 6 contacts and over back contacts of relay XX to ground through the condensers of the first register group RGI whereby any charged condenser in the group will be discharged and, will also establish an operating circuit for sequence relay X which may be traced from battery, through resistance RI, No. 6 contact of relay Z, the No. 8 front contact of relay CA, the No. 3 back contact and upper winding of sequence relay X to ground. Relay X will thereupon operate, lock in a circuit from battery through its lower winding and No. 4 contact, the

No. 3 contact of relay Z to ground at the No. 7 contact of relay CA and will establish the operating circuit of transfer relay XX.

With relays CA and XX operated a discharge circuit for any charged condenser of group RG2 is established over a lower contact of relay CA, a front contact of relay XX and a back contact of transfer relay YY. A circuit is also established from battery through resistance RI, the No. 6 contact of relay Z, the No. 8 front contact of relay CA, the No. 3 front contact of relay X, thence through the No. 4 back contact and upper winding of sequence relay Y to ground whereupon relay Y operates, locks to the locking circuit of relay X and causes the operation of transfer relay YY. With relays CA and YY operated, a discharge circuit for any charged condenser of group RG3 is established over a lower contact of relay CA and front contacts of relays XX and YY.

As soon as relay Y operates an operating circuit for relay Z is established from battery, through resistance RI, thence as traced over the No. 3 front contact of relay X, the No. 4 front contact of relay Y to ground through the upper winding of relay Z and relay Z operates, locks under the control of relay CA, causes the operation of relay ZZ and opens the locking circuits of relays X and Y which thereupon release in turn releasing relays XX and YY.

If the transmission of impulses is taking place at the time relay CA operates, ground connected to conductor FZL over the No. 1 contact of relay CA causes the operation of relay FZ to remove ground from start conductor STL to release relay B and thereby arrest the transmission of further impulses.

Relay CA is shunted by a non-inductive resistance which makes it sufficiently slow to release to insure a complete cancellation of the registered line number even if the release key RK is only momentarily operated.

What is claimed is: I

1. In a signaling system, a digit recording device, a plurality of groups of condensers, means controlled by said recording device for selectively placing condensers of successive groups in a positively or negatively charged condition to register successively recorded digits, any selected condenser of each group being positively charged to register a certain digit value or negatively charged to register a different digit value, impulse transmitting means and means controlled by the charged condensers for causing said impulse transmitting means to successively transmit series of impulses, the number of impulses in each series depending on the particular condenser of a group having a charge thereon and upon the polarity of said charge.

2. In a signaling system, a keyset, a plurality of groups of condensers, means controlled by the successive operation of keys of said keyset for selecting successive groups of said condensers, further means controlled by operated keys of said keyset for placing a condenser of each selected group in a positively or negatively charged condition to register the digits keyed, any selected condenser of each group being positively charged to register a certain digit value or negatively charged to register a diiierent digit value, impulse transmitting means and means controlled by the charged condensers for causing said impulse transmitting medium to successively transmit series of impulses, the number of impulses in each series depending upon the particular condenser of a group having a charge thereon and upon the polarity of said charge.

3. In a signaling system, a digit recording device, a group of condensers for storing digits, means controlled by said recording device for charging any one of said condensers negatively to store certain digits, a condenser of larger capacity than said storing-condensers, means for charging said latter condenser, and means controlled by said recording device for discharging said latter condenser into any one of said storing condensers to charge said storing condenser positively to store certain other digits.

4. In a signaling system, a digit recording device, a group of five condensers for storing digits, means controlled by said digit recording device for charging any one of said condensers negatively to store digits 1 to 5, inclusive, or positively to store digits 6 to 0, inclusive, impulse transmitting means, impulse counting means, two oppositely polarized relays associablewith successive ones of said condensers by said impulse counting means, one of said relays being operable by the discharge of a positively charged condenser when five less impulses than the numerical value of the digit stored have been transmitted, and means controlled by said one relay and said impulse counting means for operating said other relay to terminate the operation of said impulse transmitting means when five additional impulses have been transmitted, said other relay being the digit registered is more than five when five less impulses than the required number have been transmitted for releasing said counting relays, means thereafter effective for again rendering said counting relays successively operable under the control of said impulse generating device to count five additional impulses, and means controlled by said counting relays for terminating the, transmission of impulses when the total number transmitted corresponds to the numerical value of the digit registered.

impulse transmitting means for successively operating said sequence relays comprising a control relay, a condenser, a charging circuit for said condenser completed upon each operation of said control relay, and a discharge circuit for said condenser completed successively through the windings of said sequence relays upon successive releases of said control relay.

7. In a signaling system, a digit recording device, a plurality of registers for storing digits,

means controlled by said recording device for selectively setting said registers .to store successively recorded digits, an impulse transmitting means, an impulse counting means, a train of sequence relays, means controlled by said recording device for successively operating and locking said relays during the storing of digits to suecessively associate said registers with said record ing device, means to release said relays following the setting of said registers,,and means controlled by said impulse transmitting means for reoperating said control means for successively reoperating said relays during the transmission of impulse series to successively associate said registers with said impulse counting means.

8. In a signaling system, a digit recording device, a plurality of registers for storing digits, means controlled by said recording device for selectively setting said registers to store successively recorded digits, an impulse transmitting means, an impulse counting means, a train of sequencerelays, means controlled by said recording device for successively operating and locking said relays during the storingof digits to successively associate said registers with said recording device, means to release said sequence relays following the setting of said registers, and means controlled by said impulse transmitting means for reoperating said control means for successively reoperating said sequence relays during the transmission of impulse series to successively associate said registers with said impulse counting means, said control means c'omprising a relay, a condenser, a charging circuit for said condenser completed upon each operation of said relay in response either to the recording of a digit in said recording device or to they transmission of series of impulses, and a discharge circuit for said condenser completed successively through the windings of said sequence relays upon successive releases of said control relay in response either to the completion of the recording of each digit orto the completion of the transmission of each series of impulses.

MAURICE s. SNELL. ESMON'D P. G. WRIGHT. 

